Are Generic Drugs Safe for Cats?

By Nicholas Lansing

Lily, a mature black-and-white feline, meowed constantly and ate voraciously yet never seemed to gain weight. After several tests, results showed that Lily was suffering from hyperthyroidism, a thyroid gland disorder. The treatment options seemed like night and day in terms of cost: an expensive brand-name drug or a pocketbook-friendly generic version. For Lily’s elderly, budget-conscious owner, the choice was clear.

Lily wound up taking a drug called Methimazole, the generic version of a brand-name medication named Tapazole. The cost difference? $4 a month for the generic version instead of $60 a month for the branded product. Nevertheless, Lily’s owner was concerned by the safety of “generic.”

A Human Drug ConnectionLily’s veterinarian, Dr. Kristine Hoyt, who runs Cats on Call in Scarborough, Maine, eased the fears by explaining that both medications were developed and intended for humans. Because there’s no equivalent just for cats, they would rather treat Lily with the generic medicine, adjusting the dosage for the cat’s small, 13-pound body. Dr. Hoyt added that relying on generic drugs -- mostly from the world of human medicine -- to treat companion animals wasn’t at all uncommon.

Mary Lynch, a doctor of pharmacy at Cornell University Hospital for Animals in Ithaca, N.Y., agrees. “We use human drugs, including generics, very frequently in cats and dogs,” Dr. Lynch says. Developing a drug for a major illness, such as cancer and hyperthyroidism, involves massive costs, which often prevents companies from bringing an original, cat-specific drug to market. Under the Animal Medical Drug Utilization Clarification Act (ANDUCA), veterinarians can use human drugs in companion animals when the animals would suffer, or even potentially die, without treatment.

What’s in a Name?“When you buy the brand, you buy the fancy packaging,” says Arnold Plotnick, DVM, a board-certified feline specialist in New York City. He says generic drugs work perfectly on both cats and humans. Two key points to remember are:

A generic drug is the same as the brand-name version. It must be bio-equivalent to the original, meaning that the active ingredients are identical. It also has to have the same strength and address the same symptoms. Additionally, generic drugs should be metabolized by the body in a similar way.

A human drug can be approved for use in pets, providing owners with generic medication options. To market a human drug specifically for cats, a company must file a “new drug” application through the FDA’s Center for Veterinary Medicine. The ingredients and manufacturing process are tested, just as they were during the original testing of the human drug. Dosages may then change to match a cat’s needs.

Cats Require Special CareA generic drug made for a human might not go down so well with a stubborn cat. The few generics on the market specifically for cats are often flavored or coated to help cats swallow them. But because the majority of drugs that veterinarians use are of the human variety -- be they generic or brand name -- they’re often bitter to a cat. Dr. Plotnick often chops or grinds the pills to make them somewhat palatable for kitty. “I’ll make it up as a liquid so I can squirt it into the cat’s mouth,” he says. “Since I know the generic works, I don’t have any fear of it not being effective.”

Dr. Hoyt points to another fact about cats: They metabolize numerous drugs very differently than many other species do, and some cats experience side effects with any drug administered.

More Options on the HorizonSome companies are now focused on the development of generic drugs specifically for animals. These medications usually still derive from branded human drugs, according to Jean Hoffman, founder and CEO of Putney Inc., a Portland, Maine-based company that aims to develop generic versions of commonly used drugs. “There is a tremendous need to bring to market dosing and flavors that are right for cats, and we’ve focused on doing that,” she says.

Dr. Hoyt points to the June approval of Felimazole, a feline-specific drug that Lily could have taken. It’s dosed specifically for cats, which means you and your veterinarian won’t have to chop it up. And the pill is sugar-coated to mask the bitter taste of the drug. That should make the cat patient a whole lot happier and more willing to swallow it.

“Now I don’t have to worry about client stress, and I know that my patient is getting a drug at the right dose, in the right concentration,” says Dr. Hoyt.

is a former senior editor at Time Inc. He has written about cats and dogs for the Humane Society of the United States and contributes to many national magazines.

Posted on November 9, 2010

Posted on March 25, 2010

Grace says: My cat Lucy suffers from skin alergies & our vet has tried everything to stop her from scratching to the point of mutilating herself! She's taken steroids, antibiotics nothing helps. Can I gave her human allergy pills? And if I can what and what dose? Please help!!!
Itching kitty in NH